Scanning devices and scanning techniques are becoming increasingly popular in miniature visual displays to create an integrated image from an image source having a minimal number of pixels. In addition, scanning devices and techniques are becoming increasingly popular in sensing and tracking devices, and in the fields of optical computing, optical switching, optical storage and optical communications. Of relevance in the reduction in size of the image sources utilized in many of these devices, is the user's ability to process and integrate information, and the speed at which the information is able to be processed and integrated.
With regard to visual displays, the human visual system can process information no faster than approximately 60 Hz. Therefore, an image that is projected and scanned within 1/60th of a second to varying positions within a visual display is seen by the eyes of the viewer as one enlarged integrated image. This process, more commonly known as time-multiplexed imagery, can be utilized in the field of display technology through the use of scanners or beam steerers, and more specifically in the development of enhanced resolution miniature visual displays.
Scanning, or beam steering, devices utilized today can be found in many forms, most commonly continuous scan electro-mechanical or electro-optical scanners incorporating mirrors, galvanometric scanners, polygonal scanners, piezoelectric scanners and resonate scanners. Many of these types of scanners are quite large in size, therefore not amenable to the incorporation into a device that is small, lightweight, operates with low power consumption and is meant to be portable in nature. In addition, these scanners are complex and thus expensive to manufacture and in many instances utilize great amounts of power during operation.
Recent invention has brought about new scanning devices that are capable of being fabricated small enough in size and power requirements so as to be incorporated into portable products, such as pixellated and non-pixellated miniature scanners or spatial light modulators. Pixellated scanning devices generally require the use of a large number of interconnects to drive the device and achieve the desired number of phase changes. For instance, during operation of a pixellated miniature scanner of this type, varying voltages are required to be exerted upon specific areas of a liquid crystal cell dependent upon the phase shift required for that particular area of the cell. The result is a very complex drive circuitry where the required scanning angle and scanning aperture are large. In addition, non-pixellated scanners typically are capable of scanning over only two positions instead of continuous scanning. As a result of the large number of interconnects and extensive lithography required, manufacturing costs are increased.
Thus, there is a need for a small, fast speed, low power digital scanning device composed of a stack of individually addressable scanning elements, the scanning elements in combination allowing for the continuous /steering, or scanning, of light passing therethrough over many positions in response to the phase information recorded in the scanning elements during fabrication. Phase information is created under the influence of a ramp voltage applied thereto the individual scanning elements during operation, because of an induced change in the polarization of light passing therethrough by an applied voltage, or any combination thereof.
Accordingly, it is highly desirable to provide for a scanning device, that utilizes a plurality of individually addressable scanning elements, or liquid crystal phase spatial light modulator elements to deflect or displace the light passing through. The digital scanner allows the scanning of light passing therethrough over many positions in response to digital input signals which serve to turn "ON" and "OFF" the individual scanning elements according to the desired results.
It is a purpose of the present invention to provide a new and improved digital scanner for display resolution enhancement that is capable of deflecting light passing therethrough.
It is a still further purpose of the present invention to provide for a digital scanning device that is capable of deflecting or displacing a beam of light passing therethrough dependent upon the state of operation of the individual scanning elements which compose the device, more specifically due to digital input signals received by the device and/or the polarization of light passing therethrough.
It is a further purpose of the present invention to provide a digital scanner capable of incorporation into a new and improved visual display system for display resolution enhancement, thereby allowing for the incorporation of the scanner into miniature visual displays.
It is yet another purpose of the present invention to provide a digital scanner capable of use in optical switching systems, optical storage systems, optical computing systems, optical communications systems, data communication and telecommunication systems, sensing and tracking systems, or the like.